System for supplying liquid fuel to a



Feb. 7, 1956 D. R. TROWBRIDGE 2,733,569 SYSTEM FOR SUPPLYING LIQUID FUEL.

TO A COMBUSTION CHAMBER Filed Feb. 9, 1955 SYSTEM FDR SUPPLYING LIQUID FUEL TO A CUMBUSTION CHAMBER David Roy Trowbririge, Elm Grove, Eornchurch, England, assignor to The Plessey Company Limited, liford, England,a British company Application February 9, 1953, Serial No. 335,636

3 Claims. (Cl. fill-39.14)

This invention relates to a system for supplying liquid fuel to a combustion chamber.

When burning liquid fuels of the kind which will burn in the absence of air for example, a fuel of the general type known in the art as a mono-fuel in a combustion chamber to produce high velocity gases it has been found that if an electrically driven pump is used the current consumption to drive such a pump is high which requires the use of plant which is not only heavy but may occupy valuable space.

An object of this invention is to dispense with an electrically driven pump.

For the initial starting of the turbo-pump, a cartridge operated starting device fitted with a single or multiple breech may be incorporated in the system whereby the pressure of gas generated by the firing of a cartridge is supplied to the main combustion chamber and to the turbo-pump. The hot gasses produced also serve to ignite the fuel delivered to the combustion chamber from the pump and the pump will continue to operate by means of the gas pressure produced by the burning of the liquid fuel in said combustion chamber.

The cartridge must be designed to generate gas pressure for a sufiicient length of time to start up the turbopump, and to keep it running until the liquid fuel is admitted to and burned in the combustion chamber to provide continuation of operation.

If desired a fuel control device may be operatively associated with the pump whereby fuel delivered to the combustion chamber is regulated.

The invention will now be described with reference to the accompanying drawing which illustrate one embodiment.

Referring to the drawing:

A cartridge firing mechanism l'is connected by a pas sage or inlet 2 with a combustion chamber 3 having downstream therefrom a turbine 4a for actuating a driven element 4.

The chamber 3 is connected by passageway 5 with a v turbine driven pump 6.

A tank 7 containing liquid fuel is connected to the inlet of the pump 6 by a pipe 8, and the outlet from said pump 6 communicates via passage 9 with an electrically operated piston valve 10. The valve 10 has two branch passages or discharge outlets 11 and 12.

The branch passage 11 is attached to a flow control valve 13 and passageway 14 leading to the combustion chamber 3. The other passage 12 is' connected to a bypass 15 leading from the control valve 13 back to the tank 7. a

The control valve 13 is spring loaded to enable the valve to move under pressure of the liquid fuel so that excess fuel can flow through the by-pass 15 back to the tank 7. The amount of liquid fuel supplied by the pump 1 6 is generally in excess of normal requirements, consequently the spring loading of the control valve 13 is such 1t ihat the correct amount of fuel can pass through the ori- United States Patent An electric circuit is provided for operating the system which contains a supply 16, switch 17 and a press button switch 18. 1

In operation the switch 17 is first closed to supply current to the solenoid 19 when the piston valve 10 closes the passage 12 and opens passageway 11. Next the press button switch is depressed to detonate a cartridge 20 causing pressurized hot gases to be forced into the combustion chamber 3. Some of these gases serve to drive the turbopump 6 thereby providing the initial starting of the turbine 4 and pump also causing liquid fuel to be drawn from the tank 7, through passage 9, valve 10, passageway 11, orifice 21 in the flow control valve 13, passage 14 to r the combustion chamber 3 where it is ignited by the hot gases therein.

After the initial starting, both these elements continue to function by the supply of liquid fuel to the combustion chamber 3 and some of the combustion gases therefrom drive the pump 6.

The exhaust gases from the combustion chamber 3 and turbo driven pump 6 are discharged through the respective exhaust pipes 22 and 23.

To shut down the plant it is only necessary to open the switch 17 when the solenoid valve 10 closes the passageway 11 and opens passageway 12, thereby shutting ofi the supply of liquid fuel to the combustion chamber and per mitting fuel drawn from the tank 7 to be by-passed back again to tank 7 during the final stages of running down of the pump 6.

I claim:

1. In a liquid fuel supply system, a cartridge firing device, a combustion chamber adapted to be initially supplied with pressurized exhaust gases from said cartridge firing device, a turbine downstream from said combustion chamber and adapted to receivecombustion products therefrom to drive said turbine for actuation of an element operatively connected thereto, a turbo-pump, supplementary pressurized gas conducting means connecting said turbo-pump with said combustion chamber, a low pressure liquid fuel supply connected to said pump, and means including a flow regulating valve for conducting fuel from said pump to said combustion chamber.

2. In a liquid fuel supply system, a cartridge firing device, a combustion chamber adapted to be initially sup plied with pressurized exhaust gases from said cartridge firing device, a turbine downstream from said combustion chamber and adapted to receive combustion products therefrom to drive said turbine for actuation of an element operatively connected thereto, a turbo-pump, supplementary pressurized gas conducting means connecting said turbo-pump with said combustion chamber, a low pressure liquid fuel supply connected to said pump, means for conducting fuel from said pump to said combustion chamber and including a by-pass connection to said fuel supply, an electrically actuated flow'regulating valvein References Cited in the file of this patent UNITED STATES PATENTS 2,447,758 Lubbock a a1 Aug. 24, 1948 r 2,457,595 Orr Dec. 28, 1948 2,559,006 Clapham Iuly 3, 1951 

